From b43fbe2aab5332041c69543d512ab5ca745ddd8e Mon Sep 17 00:00:00 2001
From: Kathy Chen <kxchen@google.com>
Date: Mon, 8 May 2023 23:23:16 +0000
Subject: [PATCH] Revert "Revert "[AC] Fix NPE. If the client sends multiple
 unregister requests at the same time, the client request could be null before
 the next request is processed.""

This reverts commit f470e292d858cd1bbd688d7398beb2dabd2622ac.

Reason for revert: Fixed warning from presubmit

Change-Id: I3e1ea17a2e149b548885666d9e8418647b96439e
(cherry picked from commit b93d2ce0d3a7d580f2897c32d446c22e288d3002)
Bug: 278891267
Test: make
---
 .../server/ambientcontext/AmbientContextManagerService.java    | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/services/core/java/com/android/server/ambientcontext/AmbientContextManagerService.java b/services/core/java/com/android/server/ambientcontext/AmbientContextManagerService.java
index a9a77bf28ebec..c6b15b6dcd7aa 100644
--- a/services/core/java/com/android/server/ambientcontext/AmbientContextManagerService.java
+++ b/services/core/java/com/android/server/ambientcontext/AmbientContextManagerService.java
@@ -60,6 +60,7 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Objects;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 
 /**
  * System service for managing {@link AmbientContextEvent}s.
@@ -595,7 +596,7 @@ public class AmbientContextManagerService extends
 
             synchronized (mLock) {
                 for (ClientRequest cr : mExistingClientRequests) {
-                    if (cr.getPackageName().equals(callingPackage)) {
+                    if ((cr != null) && cr.getPackageName().equals(callingPackage)) {
                         AmbientContextManagerPerUserService service =
                                 getAmbientContextManagerPerUserServiceForEventTypes(
                                         UserHandle.getCallingUserId(),